Karteikarten
Relational Databases
Karten in diesem Stapel (20)
- 1What is an entity?A real world object which can have information stored about it
- 2What are attributes?Details about the entity
- 3What are relationships?They connect separate tables that have things in common
- 4What are the columns of a database table called?The fields
- 5What are the rows of a database table called?The records
- 6What is the primary key?A filed that holds data that is unique for each record
- 7How are relational databases linked?Using primary key fields
- 8What is a foreign key?When the primary key filed from one table is included in another table so that they can be joined
- 9Benefits of relational databasesPrevent data redundancy
Does not take up as much space and memory
Does not require new data to be added every time you enter a new record - 10What is a query?A database search used to find specific records
- 11How can logical operators be used in framing database queries?They can be combined to narrow down the search
- 12What is a form?Used to enter data into a database
Only required if the database needs a user to enter data
Make it clear what data should be input - 13What is a report?Used to export data
Present data in a way that is easy to read - 14What is a module?Pre-written programs
You can edit modules in the programming language and add your own procedures - 15What is validation?Database fields have validation rules to make sure that the data entered follows the expected format
- 16What is a presence check?Checks that something has been entered
Checks the field is not empty
(required fields) - 17What is a length check?Checks that a certain number of characters have been entered
- 18What is a range check?Checks that any value entered is between a minimum and maximum value
Only applies to numbers - 19What is a type check?Checks the data type
e.g. integer, decimal, string - 20What is a format check?Checks the data follows the specified pattern of characters / digits
e.g. dd/mm/yyyy to check a date
An input mask is used to ensure that the data is in the required formated
Informationen
- Beschreibung
- GCSE Computing (5 Databases) Karteikarten am Relational Databases, erstellt von Anisha Rai am 13/04/2016.
- Erstellt von
- Anisha Rai
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- 24
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